Thermomechanical properties and equation of state for the γ-polymorph of hexahydro-1,3,5-trinitro-1,3,5-triazine

This work predicts the elastic modulus tensor, equation of state, and coefficients of thermal expansion at all stable thermodynamic states for γ-RDX. The work provides substantial material information for continuum modeling of RDX.

Elastic Modulus of the (GaA.s)m(A.l A.s)n Superlattices

ABSTRACTThe ultrathin (GaAs)m (AlAs)n superlattices ( SL ) grown along [001] are formally considered as a result, of ordering-type phase transition from an initial hypothetical mixed crystal (Gax Al1-x)As with x = m/(m+n) . From this point of view changes of elastic modulus tensor (EMT) induced by ordering can he calculated nearly in a spirit of phenomenological Landau theory of second-order phase transitions. It .is shown that a change of EMT component. S66 is completely determined by symmetry properties of two translational (Dzyaloshinskji) invariants of m+n power .in the expansion of SL thermodynamic potential in a power series .in order parameter components. The changes of the other EMT components depend on the second power of order parameter .The expressions are found out to connect. EMT of a definite ordered phase (SL - family with m+n = 3) with that, of the initial one.